Are there any metals or minerals in danger of becoming extinct?

June 9, 2009 12:12 PM

Are there any metals or minerals, especially ones essential to some vital industry, that are in danger or becoming "extinct"?

Say WWIII is fought over the remaining oil, and WWIV is over the remaining water, will WWV be over the last of the...vanadium?

This came up when I was debunking a technophile friend's faith in technology to bring us through the next few hundred years or so.

Him: "Well, we can certainly get off of dependency on increasingly rare and conflict-generating fossil fuels by switching to hydrogen-powered fuel cells...."
Me: "You know that fuel cells need platinum as a catalyst to function, right? You think oil is rare, where are we going to get all that platinum, and without fighting over it?"

Him: "silicon chips are made from sand...we're certainly not going to run out of sand!"
Me: "well, most of it is sand, but the working parts are made from rare metals and elements...sand does you no good if we've mined out all the gallium arsenide or whatever"

So I'm thinking in terms of using up all of a non-renewable resource, but in terms of materials, not fuel. All the world's dodo birds were in one spot, and we thought they were so neat we used them all up. Is there any material that we're in danger of doing the same with?

Does all the americium-231 come from a single atoll somewhere, and when we've mined it all out we won't be able to make a smoke alarm anymore? That kind of thing.

Not-reasonably-obtainable counts in this, I'd think. For instance, I've heard that there is plenty of gold dissolved in the planet's oceans, but there's no way to extract it in useful quantities.

posted by penciltopper to Science & Nature (24 answers total)

I've heard copper supplies are dwindling?
posted by sully75 at 12:21 PM on June 9, 2009

The aptly-named Durn Bronzefist were discussing this not long ago; I stumbled upon some chart but could not locate it again. He found it at http://www.newscientist.com/data/images/archive/2605/26051202.jpg. It's compounded from many sources. Sobering if even a little bit of it is true.
posted by adipocere at 12:21 PM on June 9, 2009 [2 favorites]

Theoretically we can always reclaim used material from discarded parts.
Given enough persistence and energy.
And given enough energy, theoretically we can MAKE whatever material we need.

Theoretically that is.
posted by 7life at 12:28 PM on June 9, 2009

depending on who you ask, we may be running out of indium. we may not. i understand there's some controversy around the claim. at any rate, a glance at the spot price history of indium over the last few years shows a very volatile market, which certainly implies some question about the supply.

indium is a rare element which is used in the production of transparent conductive coatings. these are a critical component of pretty much every LCD screen you see, and to a lesser extent, high-efficiency solar cells. also, CIGS (copper indium gallium diselenide) solar cells are being increasingly commercialized, imposing even more demand. there are alternatives, but they are less developed and less attractive for a variety of reasons.
posted by sergeant sandwich at 12:31 PM on June 9, 2009

Well here's the thing: most of this stuff is recyclable. Metals, especially when used as catalysts, don't actually get used up. So while it's at least theoretically possible that we might exhaust all readily available quantities of a particular metal in known deposits--never underestimate the possibility of finding new deposits though--most of that metal just winds up getting thrown away somewhere. So yeah, copper mines are starting to run out, but they aren't in the same category as, say, fossil fuels, which are burned. We might have to reconstitute rarer metals from existing uses, or just go nuts mining our landfills, but most of the stuff we've mined is still out there somewhere, in some form.

So all that iron/copper/gold/whatever we've mined? Yeah, a lot of it is in use, but a lot has been thrown away and is currently rusting somewhere. Getting iron out of rust isn't cheap, but it isn't impossible either. So while the resulting materials will be more expensive than they would be if they had been mined, there isn't like an "Oh, shit, we're completely out of [insert metal of choice]!" situation pending.

This doesn't apply to radioactives. Those do get used up, just like fossil fuels. Once we're out of uranium, that's basically it. No nuclear power until we go straight to fusion. So while switching to nuclear power probably is a great short-to-intermediate term solution to climate change, it's no permanent solution.
posted by valkyryn at 12:34 PM on June 9, 2009

Not a metal, but supposedly helium is vulnerable to shortage.
posted by mhum at 12:36 PM on June 9, 2009

There's an important difference between oil and most elements. Oil is destroyed by consumption, whereas most elements are not. Lots of elements that we "consume" would be recycled/recovered if there were sufficient demand. For example, if we switched to hydrogen fuel cells, presumably more of the platinum in catalytic converters in gasoline powered cars would be recovered.

Which is not to say that shortages of certain elements won't cause problems. A lot of times recovering these elements is a pretty dirty and energy intensive process.

So I think for your argument, you need to look for elements whose recovery cost with known technology is too high, even given increased demand.

(on preview, basically what valkyryn said)
posted by justkevin at 12:49 PM on June 9, 2009

I can't google a source, but I'd imagine there's lots of minerals & the associated essential elements dissolved in ocean water, and as ocean sediment. The proportions may be minuscule, but as an absolute quantity it is probably enormous. If money is no object......
posted by TDIpod at 12:53 PM on June 9, 2009

Americium-241 is made when plutonium-240 absorbs a neutron and then beta decays. Plutonium is made the same way, from uranium. So the relevant material there is the supply of uranium (and the supply of nuclear reactors, which is more of a sociopolitical question). But that's hardly the only way to build a smoke detector; it just happens to be pretty effective and pretty safe and pretty cheap. Some people prefer optical smoke detectors.

Indium is a good example of a rare material whose unique physical and chemical properties make impractical things practical. sergeant sandwich mentions its manufacturing uses. I've used indium to make high-vacuum seals: it's flexible and flows into gaps. I'm sure there are other uses.

Scarceness generates creativity, though. Apart from fuel (which, in the end, determines cost) it's possible to engineer your way out of just about any corner.
posted by fantabulous timewaster at 12:57 PM on June 9, 2009

You know that fuel cells need platinum as a catalyst to function

A catalyst, by definition, is something that's not used up by a chemical reaction. Just because today we're throwing away catalytic converters whenever we throw away a whole car (and we don't, at least some of the time) doesn't mean we have to. Granted, there's an energy cost to recycling it, but platinum isn't disappearing in the same way that, say, oil is. It's still out there somewhere, and it can pretty much be used indefinitely.

Which isn't to say that your concerns are unfounded (if we choose not to recycle platinum, we're no better off than if we couldn't recycle platinum), but to ignore the possibility of recycling materials better than we currently do paints an excessively negative picture. Note the right-hand side of the graphic adipocere links: 49% of our aluminum usage is currently met by recycled aluminum. Can we do better? Almost certainly, and the better we do at that, the less aluminum we have to dig out of the ground, and the longer it lasts.

Note: recycling arguments may not apply to radioactive materials (e.g., uranium) which are in fact used up. Then again, it depends on the isotope: ²⁴¹Am, used in smoke detectors (not ²³¹Am) has a half-life of over 400 years, so as a source of ionizing radiation useful for smoke detection, it can be used for quite some time.

There's also the fact that increased demand for some materials sometimes means decreased demand for others: "Photography used 30.98% of the silver consumed in 1998 in the form of silver nitrate and silver halides... The use of silver in photography has rapidly declined, due to the lower demand for consumer colour film from the advent of digital technology, since in 2007 of the 894.5 million ounces of silver in supply, just 128.3 million ounces (14.3%) were consumed by the photographic sector, and the total amount of silver consumed in 2007 by the photographic sector compared to 1998 is just 50%."
posted by DevilsAdvocate at 12:59 PM on June 9, 2009

We do have other radioactives for fission. Once we run out of uranium, we have *single thump on the Thorium Drum*.

However, recycling is not necessarily a solution. An answer, yes. It's the energy equivalent of those folks who say "we'll never actually run out of oil. It's just that the last few barrels of crude will cost a million bucks each. They will remain forever unsold, so we will not have run out."

Right now, we're digging out of the ground "free" energy in an easily transportable form. After we run out of that, we'll have a tough time getting to hit the "all renewable" point if we do not have everything just so. If we do not hit a certain energy production level, aided by some combination of fusion, fission, solar, etc., by a certain time, our infrastructure will devolve enough such that we will not easily be able to build the solar panels to pull the iridium out of the sea to build the solar panels. It's something of a race.

Look to the right on that chart to which I linked — recycling was prominently mentioned.

Hell, given particle accelerators, with enough energy you can transmute elements. Lead to gold. It's just tremendously impractical to do so.
posted by adipocere at 1:05 PM on June 9, 2009

Helium is a non-renewable resource and is being depleted quite quickly. Because of its extremely low density, when released into the atmosphere it rises up to the very top and (I'm told) is lost into space.

It is produced on geologic timescales from the radioactive decay of heavier elements — which is why there's any inside the earth at all — but on human or even civilization timescales it's thoroughly non-renewable, except perhaps in very small quantities from nuclear reactors.

Aside from birthday balloons, helium is critical to anything that needs to be supercooled to operate. Think superconductors. In particular, think MRI machines. Each MRI machine has several gallons of liquid helium in it, and it must be periodically replenished as it evaporates.

Although it's possible that Science might develop higher-temperature superconductors that will gradually reduce the amount of liquid helium necessary for MRI machines, it's not a sure thing, and there are almost certainly experiments and avenues of research that will become much harder without it. Not even liquid hydrogen has as low a boiling point as liquid He; I'm not sure what, if any, replacement for it as a cryogenic coolant there might be.

The U.S. was at one point maintaining a National Helium Reserve, and pumping the excess helium extracted from underground natural gas pockets into old salt mines for long-term storage, but that program has been discontinued, and the helium will be sold off and the infrastructure dismantled. I think it's basically predicted that when we run out of natural gas, we will basically run out of cheap helium as well. (There might be more left in the earth, but since its extraction won't be subsidized by natural gas drilling anymore, it will be phenomenally expensive in comparison.)
posted by Kadin2048 at 1:16 PM on June 9, 2009

I'm bothered by helium and indium, personally.

...so bothered, in fact, that I sort of feel helium balloons are immoral. Not that I stop the kids or anything; I just feel uneasy about it.
posted by aramaic at 1:35 PM on June 9, 2009

The only one I can think of that wasn't already mentioned was halfnium. There isn't much of it and it's hard to refine. There was virtually no demand for it until Intel started using it as magic sauce in its 45nm process. But like most metals it can probably be recovered from old discarded equipment. Helium though... yeah once that's gone, it's gone.

I'm more concerned with our fresh water supplies though.
posted by chairface at 1:38 PM on June 9, 2009

Sort of a piggyback: What about elements needed for agriculture? Plants need nitrogen and phosphorus, for example. I don't know where the nitrogen in our soil comes from, but I think I read something the other day about phosphorus having an average of 46 cycles on land before it ends up washing into the oceans where it goes through hundreds of cycle before ultimately resting on the bottom of the ocean for the millions of years it takes for plate tectonics to get it back to a place we can use it. That would mean that the intensive agriculture necessary to support billions of people would use up the phosphorus more quickly than the movement of the seabeds replenishes it. So, if that's the case, and if phosphorus is necessary for the agriculture that supports human life, then, while it wouldn't be "used up" it seems like it would take quite the technological leap to circumvent the problem.

I'm certainly no expert on these matters, but maybe someone here is who can back me up or call bullshit.
posted by Quizicalcoatl at 1:38 PM on June 9, 2009 [1 favorite]

Indium is the one I had heard about, in particular in relation to CIGS solar cells. I believe one of the major pluses of thin-film solar cells (Nanosolar, etc.) is their greatly reduced usage of these expensive/rare materials for equivalent generation capacity.
posted by madmethods at 1:46 PM on June 9, 2009

I don't know where the nitrogen in our soil comes from

The atmosphere. It's 78% nitrogen, after all.

OK, that's basically correct, but it's not quite that easy. Nitrogen in the atmosphere is molecular nitrogen (N₂) which is pretty inert and breaking those two atoms apart and getting the nitrogen atoms into a form usable by life is not the easiest thing in the world.

The ultimate source for nitrogen in living organisms, for most of this planet's existence, has been nitrogen-fixing bacteria. There's certain bacteria which can convert molecular nitrogen to useful nitrogen, and it's entirely from them that all the nitrogen in all living things was ultimately derived. (Well, virtually all; there's a few other very minor natural sources and processes.) Until the early 20th century, when the Haber process was discovered, and mankind was able to produce biologically useful nitrogen without the use of nitrogen-fixing bacteria. Much of the nitrogen in agricultural fertilizer today is the result of the Haber process, which is essentially limited only by how much energy we have available for it. (There's also an attendant problem on the other end, in that excessively nitrogen-rich agricultural run-off can cause various environmental problems.) I don't think nitrogen is too much of a worry as long as we have clean energy to support the Haber process (or else go back to traditional fertilizers) and (unlike the way agriculture is currently practiced) don't use excessive amounts of fertilizer.

As for phosphorus, here's a few articles on the phosphorus cycle and the effect of modern agricultural practices on it. It looks like your understanding is correct: once we run out of land-based phosphate minerals to generate fertilizer from, the phosphorus runs to the oceans and spends a long time there (either in aquatic life or in underwater minerals), and the underwater minerals are harder to mine. I don't have a good sense of what timescale that's likely to be a problem at, however.
posted by DevilsAdvocate at 2:40 PM on June 9, 2009

You're right to bring up agriculture; oil is used heavily for the production of pesticides, which drastically increases crop yields - yields could easily be half as much if it weren't for pesticides, which is a problem, as pretty much all of the arable land is already being used for agriculture.

One natural method for of getting nitrogen into the soil in usable form such as ammonia and nitrates is nitrogen-fixing bacteria (using the plentiful inert nitogen in the air), mostly working in symbiosis with the legume family (clover, beans, alfafa). This is the basis for crop rotation. Another source is animal waste, though it's difficult to store and transport. A very common method though is using nitrate fertilisers based on fossil fuel natural gas i.e. methane found alongside oil, or in separate fields - again, this heavy industrial use of fertilizers makes possible our current levels of agriculture.

The primary source of phosphates (which are essential to life, and thus agriculture) is apatite, a class of phosphate minerals. The largest source for these is in Morocco, though there are deposits in a number of places, including the US. Some scientists estimate we're facing 'peak phosphorus' in 30 years, with reserves being practially exhausted in 50-100 years, with biofuels indirectly using it up at an incredible rate.

The biggest current worry though is helium, as mentioned. That stuff is very useful, not easily replaceable, and once extracted, it's just gone. No recovery from landfill!

With regards to recycling, it's not automatically a panacea; many of the chemicals/minerals used in modern electronics are highly toxic. Dumping them in landfill allows the lead, mercury and cadmium to potentially leech into the soil and poison the water table. Yet recycling often means they end up with the cheapest bidder, and end up being illegally imported to be crudely recycled in china or the like by some of the very poorest people for the copper and gold, while the toxic stuff goes straight into runoff and the air - they even burn the plastic to make it easier to get the metals out, and the smoke is cancerous.

The thing about indium is that there isn't that much left of it in it's currently extracted form, from zinc ore waste. It is however available alongside other metals such as tin and copper (though somewhat harder to extract), and is 3 times more abundant than say silver, which we extract at 40 times the rate of indium. As the price rises, other forms of extraction, including direct mining become economical. This isn't the same principle as the last billion dollar barrel of oil, but more the economics of oil fields that became available at $40 a barrel that weren't at $20 a barrel.

Its main use is as a transparent conductor in LCDs, as indium tin oxide - before that, we hardly used it. Graphene based conductors are looking pretty promising as a much cheaper alternative, and may well supplant it in the near future. That would leave our remaining supplies usable for CIGS without a guilty conscience, for now.

Of course, in the long run (200 years+) we're going to run out of a huge amount of materials that we use for our industrial society right now. While landfill-diving and much better recycling will push that out further, there will come a limit where things we want and need simply aren't available for further production. As we approach that point, I really really hope we've developed a low-energy renewable-energy recycling economy and a functional asteroid mining program, or we're really screwed as a species - and if we did get knocked back to a low-industrial society or worse by a major global war, it'd be virtually impossible to build back up as all the easy-access deposits and advances made possible by them would be gone.
posted by ArkhanJG at 3:15 PM on June 9, 2009

By the way, that graph is a little misleading adipocere; it appears based upon reserves that are currently used, as opposed to new sources. So indium as currently extracted from zinc would run out in 4 years if everyone used it at the same rate as the US, but other sources will extend that significantly.

The same goes for uranium; much of the current usage comes from previously mined and stockpiled ore, simply because there wasn't that much demand given the move away from nuclear plants. Now we're going back towards nuclear, it's worth reopening old mines or making new ones; we've got several hundred years worth in relatively easily accessible ore we already know about even with a big spike in demand, and as prices rise making other areas worth digging, we've potentially got thousands of years worth of mineral available.
posted by ArkhanJG at 3:30 PM on June 9, 2009

No cite for this, but I once read that tin mines in Cornwall used to close because they were mined out, then reopen some years later, as it became profitable to mine lower-quality ore, tin becoming a bit scarcer. I figure someday, they'll mine dumps for the aluminum, plastic, etc.

Not all wars are about resources. Sometimes they're about boundaries, and often they're about culture/religion. We're unlikely to run out of reasons to go to war. that's so sad.
posted by theora55 at 5:42 PM on June 9, 2009

No idea about the truth of this, but Kunstler recently said

For both the hybrid and the electric car, the issue of how to get enough lithium for the batteries obtains, at least for now, given the current state-of-the-art battery technology. Most of this rare metal now comes from one place, Bolivia, and everybody wants "a piece" of it.

Does Lithium wear out when used in batteries?
posted by Rash at 6:45 PM on June 9, 2009

There is a argument that no resource can fully deplete itself. As stocks dwindle, prices rise, and consumption decreases. I'd probably be on your technophile friend's side because the argument follows that as the price of some resource rises, more substitutes emerge (either by increased technological effort or simply making previously-unprofitable substitutes profitable): for instance, oil shale as a source of oil-derivatives as the price of light sweet crude oil rises.
posted by SamuelBowman at 12:51 AM on June 10, 2009

Does Lithium wear out when used in batteries?

Only in the sense that iron wears out when it rusts. That is, extracting the pure metal again is expensive.
posted by fantabulous timewaster at 9:58 AM on June 11, 2009

The July/August 2009 issue of Discover magazine has an article (p. 66) on metals used in modern technology that touches on some aspects of your question.

Metals covered are tantalum, lithium (according to the article Bolivia does not currently have any mines but has many reserves), platinum, various rare earth metals (yttrium, europium, neodymium, etc.), indium, and palladium.

I suspect price fluctuations of indium may have as much to do with anticipated demand for more solar cells and accompanying speculation as concern over the supply of indium being unsteady.
posted by yohko at 5:31 PM on June 12, 2009